var timer = null;
var offset = 5000;
var index = 0;

function slideImage(i) {
    var id = 'image_' + target[i];
    $('#' + id)
        .animate({ opacity: 1 }, 800, function () {
            $(this).find('.word').animate({ height: 'show' }, 'slow');
        }).show()
        .siblings(':visible')
        .find('.word').animate({ height: 'hide' }, 'fast', function () {
            $(this).parent().animate({ opacity: 0 }, 800).hide();
        });
}

//bind thumb a
function hookThumb() {
    $('#thumbs li a')
        .bind('click', function () {
            if (timer) {
                clearTimeout(timer);
            }
            var id = this.id;
            index = getIndex(id.substr(6));
            rechange(index);
            slideImage(index);
            timer = window.setTimeout(auto, offset);
            this.blur();
            return false;
        });
}
//bind next/prev img
function hookBtn() {
    $('#thumbs li img').filter('#play_prev,#play_next')
        .bind('click', function () {
            if (timer) {
                clearTimeout(timer);
            }
            var id = this.id;
            if (id == 'play_prev') {
                index--;
                if (index < 0) index = 6;
            } else {
                index++;
                if (index > 6) index = 0;
            }
            rechange(index);
            slideImage(index);
            timer = window.setTimeout(auto, offset);
        });
}
//get index
function getIndex(v) {
    for (var i = 0; i < target.length; i++) {
        if (target[i] == v) return i;
    }
}
function rechange(loop) {
    var id = 'thumb_' + target[loop];
    $('#thumbs li a.current').removeClass('current');
    $('#' + id).addClass('current');
}
function auto() {
    index++;
    if (index > 6) {
        index = 0;
    }
    rechange(index);
    slideImage(index);
    timer = window.setTimeout(auto, offset);
}
$(function () {
    //change opacity
    $('div.word').css({ opacity: 0.85 });
    auto();
    hookThumb();
    hookBtn();

});